It is frequently necessary to install an underground pipe between two given points on opposed sides of a finished street or driveway, for example. It is routine procedure to provide an operating trench on one side and a target trench on the opposite side. An underground pipe installer device is properly positioned and braced for operation in the operating trench.
A first rod length is manually inserted through drive jaw means of the installer device and is engaged thereby to push the first rod length toward the target trench, generally by a fluid operated cylinder and piston assembly. The trailing end of the first rod length is provided with a coupling to receive a second rod length and the drive means is actuated to push the second rod length forwardly toward the target trench. A sufficient plurality of connected rod lengths are driven forwardly until the leading tip end of the first rod length emerges into the target trench.
The leading tip end is threadedly provided with a pusher cap which is removed and replaced with an adapter for attachment to an end of a pipe to be permanently installed under the above surface. For this purpose, means are provided to reverse the direction of movement of the rod assembly to pull the pipe attached thereto backwardly through the hole, formed by the rod assembly, until the leading end of the pipe emerges into the operating trench.
The above described operations are quite conventional, however, it is essential to anchor the pipe installer device in the operating trench against the very substantial reaction forces of the rod pushing operation so as to maintain sufficient space behind the pipe installer device to accomplish the manual rod coupling and uncoupling operations which are essential in forming the hole and in withdrawing the pipe into the hole.
Heretofore, all underground pipe installer devices have been braced against the rear end vertical face of the operating trench during the rod pushing operation, and the bracing structure was then removed and engaged against the front end vertical face of the operating trench for the pipe pulling operation. Examples of such brace means are illustrated in Applicants U.S. Pat. Nos. 3,907,253, 3,988,003 and 3,988,004.
The front mounted brace means of the present invention is comprised of a generally rectangular abutment frame, formed of top and bottom rails, interconnected by vertical struts. The frame is vertically, transversely, centrally pivotally attached between upper and lower front end extensions from the device. A generally T-shaped trench is provided for the device with the main length thereof being positioned in the longitudinal portion of the T-trench with the transverse frame being positioned in the cross portion of the T-trench. The pipe installer device is thereby braced for both the rod pushing and the pipe pulling operations.
Therefore, one of the principal objects of the present invention is to provide a front mounted means for an underground pipe installer device to brace the device against the reaction forces of both a rod pushing hole forming operation, and a pipe pulling operation for installing the pipe in the formed hole.
Another object of the present invention is to provide a transverse vertically disposed abutment frame, centrally pivotally attached between upper and lower front end extensions of a main longitudinal length of an underground pipe installer device.
A further object of the invention is to provide an abutment frame comprised of upper and lower beams connected by a plurality of rigid vertical struts .